Backyard Aquaponics
A place to discuss aquaponics

Thanks royale, we are having the black poly pipe debate RE: is it safe to use at hot water temp at the moment, something also to consider.

I think the poly is pretty stable at the temps we are talking about (up to 45C or so) so shouldn't be a problem, but i have just sent an email to nylex to ask the question.

I hope they reply!!

This forum is great it helps to share the load

OK, first step made. Ill be picking up 5 220l blue drums for rain water collection and storage on saturday, when (if) full that will give me about a 80% of the system in top-up water. I may keep one back to use as a hydroponics only trial for the PVC pipe flowbeds.

Hi Royale,

I think I have the gist of what your planning and it sounds like you shouldn't have major problems...

Being an automation kind of guy, you might want to give google sketchup a try http://backyardaquaponics.com/forum/vie ... t=sketchup

It's amazing what people on the group have been producing in just a short while, and a picture paints a thousand words... Very usefull for working out design issues..

LKB, all I need is strong BIL and FIL and C1 who work for food and beverages and I'm laughing! Site supervision is my area of expertise!

That one came out of the blue - hit the wrong button did we (is there a special test that MOD's must take or summit?)

Having visited a small commercial facility last weekend, I have changed my original design substantially. It looks like it will be cheaper to build and run as a mimic of the one i saw. New design consists of-
Fish tank (1000L, gravity fed from Biofilter) into
Swirl Filter (basically a 200 odd litre bin, gravity feed) into
Solids Filter/Sump (200 screened tub gravity fed) into
Pump (3000lph) into
Biofilter (200 odd litre bin raised 2.5+meters with small holes drilled in bottom, filled with bean bag balls, suspended over a collector. Pump fed) into
Growbeds (120mm PVC as per before, no medium, always filled and flowing, gravity fed, returning to sump) and tank
Still looking at using black poly for solar heating, and just t-ing it off the pump-> bio feed line with some flow restriction, as well as supplimentary aeration.
Total cost should be about $1700 which is not bad considering.

Oh, and my book/cd/dvd arrived today, will review it for design improvements over the coming weeks

that sounds interesting wheres that one!

Royale,

I'd like to share some theories i have, keep in mind they are only theories and the conclusions i have come to may be flawed, but the glove seems to fit, as it were..............

Traditionally, all the literature around that i had seen regarding aquaponics basically said "good for herbs and leafy greens, not good for fruiting / flowering plants"

Then i saw joels setup, and if you have any doubt on the ability to produce fruits, check out the latest pic of the tommy bush in the "plan B" forum.

This didn't make sense to me, as the potassium and phosphorus levels required for fruiting are generally too low in a traditional aqua setup.

Then at the NMIT lectures one of the Drs. from UVI mentioned that if they kept their solids in the seperator and filters longer, they would get a proportionatly higher K and P nutrient levels.

Then the penny dropped, in Joels designs with the gravel grow beds, NO solids are removed EVER. My theory is that the majority of the P and K come from the solid fish wastes, as i know that most of the N comes from the ammonia --> NO3 excreted from the fish gills.

By allowing the solids to gradually break down and mineralize in the 300mm gravel, beds sufficent levels of P and K are available to produce bumper fruit (ie capsicums, tommies, etc) crops.

I'm not going to disrespect the commercial systems, but you may want to have a think about the bigger picture and cause and effect.

The more wholistic we can keep the system the better i think, far better that there is a system that allows the solids to remain insitu and add to the overall nutrient supply, than remove them via seperators and filters in my humble opinion.

Steve

The system is in kinglake victoria, the owner built a system for his PhD thesis then took his findings to go commercial, seems like a pretty successful system for its size (its 10,000L of fish tank)

Were you missing a zero there Royale? Pretty cheap for less than $1500 with all of that gear..

That sound suspiciously like Minnimurra aquaponics that you went to see, is that right?

That theory sounds pretty solid steve, and interestingly enough the system i visited was not growing flowering plants- the reason given was that the particular plants chosen were more profitable.
Another thought though, the system was geared such that it could easily maintain 55kg/m3 of fish (at 7-8ppm O2). This is achieved by high water flows and vigilance in keeping low BOD (solids removal). Trace element such as Mg, K, Ca and Fe were added to the system, not sure if anything was done about P.
I guess its just a matter of tweaking your system to what you are intending to grow, if you dont want to add trace elements all the time dont filter solids but expect a higher BOD.